We propose to test an integrative model for adolescent risky behavior that incorporates key psychological features of the transition into adolescence, the centrality of affect in adolescent risky behavior, and the role of classic, dispositional traits in shaping psychosocial learning. As individuals make the transition into adolescence, they tend to experience increases in negative affectivity, decreases in positive affectivity, increases in sensation seeking, and increases in urgency (the tendency to act impulsively when distressed). Many of these trait changes involve affectivity, which we believe is important because affect appears to play a central, if previously underappreciated, role in adolescent risky behavior (Steinberg, 2004). These trait changes are particularly important in light of advances in person-environment transaction theory. It appears that individual differences in personality cause individuals to learn different things from the same learning event: dispositional traits shape psychosocial learning (Smith et al., 2006). We propose to study the influence of trait changes on learning that disposes one to risky behaviors. We believe the trait of urgency is particularly important, because urgency reflects mood-based impulsivity and is strongly related to several risky behaviors (Fischer et al., 2003; Smith et al., 2007a; Whiteside & Lynam, 2003; Whiteside et al., 2005). In a longitudinal study of children, from 5th grade (before the start of middle school) through 8th grade, we will show the following. Following the onset of adolescence, individual differences in the growth of urgency will predict subsequent individual differences in the growth of expectancies for problem drinking and other risky behaviors. Growth in those expectancies will predict subsequent individual differences in the onset of problem drinking and the other behaviors. Urgency's role will be different from that of sensation seeking: for example, sensation seeking will predict quantity/frequency of drinking, and urgency will predict problem drinking. Urgency's role will be different from that of negative and positive affectivity: the latter two traits will predict subsequent growth in depression, but urgency will not. Urgency will predict growth in risky behaviors, but affectivity will not. PUBLIC HEALTH RELEVANCE: This research will help us understand how the transition into adolescence can leave some children at risk for beginning to engage in risky behaviors. It will highlight the importance of emotion for some adolescents' risky behaviors, and it will suggest mood-based interventions that might reduce risk.